<!DOCTYPE HTML>
<html lang="en-US">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
<script type="text/javascript">
    var x = 9,
        mod = {
            x:100,
            getX:function (y) {
                return this.x + y;
            }
        };
    var ln = {
        bind:Function.bind
    };

    console.log(mod.getX.bind(mod,3));
    console.log(mod.getX.bind(mod,3)());
    //error:Uncaught TypeError: Bind must be called on a function
    console.log(ln.bind(mod.getX,mod,3));//compare with line20

</script>
</body>
</html>